US lawmakers are adding their voices to a growing call for the controversial Dakota Access pipeline to be cancelled or re-routed as protesters at the pipeline’s construction site face harsh winter weather conditions.

In Washington, 1500 miles (2400 kilometres) from the protests near the Standing Rock Sioux Reservation on the North Dakota-South Dakota border, Nevada Senator Harry Reid, the outgoing leader of the upper chamber’s Democrats, appealed to President-elect Donald Trump to find an alternative route for the pipeline.